title: Is it possible to identify exacerbations of mild to moderate COPD that do not require antibiotic treatment?
abstract: BACKGROUND
  Anthonisen criteria are widely used to guide the use of antibiotics in exacerbations of COPD. We evaluated the best predictors of outcomes in exacerbations of mild to moderate COPD not treated with antibiotics.
  
  
  METHODS
  We used data from 152 patients of the placebo arm of a randomized trial of amoxicillin/clavulanate for exacerbations of mild to moderate COPD. Clinical response in relation to Anthonisen criteria and point-of-care serum C-reactive protein (CRP) tests (cutoff, 40 mg/L) was assessed with multivariate logistic regression analysis.
  
  
  RESULTS
  Clinical failure without antibiotics was 19.9% compared with 9.5% with amoxicillin/clavulanate (P = .022). The only factors significantly associated with an increased risk of failure without antibiotics were the increase in sputum purulence (OR, 6.1; 95% CI, 1.5-25.0; P = .005) and a CRP concentration ≥ 40 mg/L (OR, 13.4; 95% CI, 4.6-38.8; P &lt; .001). When both factors were present, the probability of failure without antibiotics was 63.7%. The Anthonisen criteria showed an area under the curve of 0.708 (95% CI, 0.616-0.801) for predicting clinical outcome. With the addition of CRP level, the area under the curve rose significantly to 0.842 (95% CI, 0.76-0.924; P &lt; .001).
  
  
  CONCLUSIONS
  Among the Anthonisen criteria, only an increase in sputum purulence is a significant predictor of failure without antibiotics. The use of a point-of-care CRP test significantly increases the predictive accuracy of failure. Both of these easy-to-obtain factors may help clinicians to identify patients with exacerbated mild to moderate COPD who can be safely treated without antibiotics in an ambulatory setting.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT00495586; URL: www.clinicaltrials.gov.
authors.affiliation: Servei de Pneumologia, Hospital Universitari Vall d'Hebron, CIBER de Enfermedades Respiratorias (CIBERES), Barcelona. Electronic address: marcm@separ.es.
authors.forename: Marc
authors.initials: M
authors.lastname: Miravitlles
authors.affiliation: Primary Care Centre Jaume I, University Rovira i Virgili, Tarragona.
authors.forename: Ana
authors.initials: A
authors.lastname: Moragas
authors.affiliation: Primary Care Centre Jaume I, University Rovira i Virgili, Tarragona.
authors.forename: Silvia
authors.initials: S
authors.lastname: Hernández
authors.affiliation: Primary Care Centre Valls, Tarragona, Spain.
authors.forename: Carolina
authors.initials: C
authors.lastname: Bayona
authors.affiliation: Primary Care Centre Jaume I, University Rovira i Virgili, Tarragona.
authors.forename: Carl
authors.initials: C
authors.lastname: Llor
mesh_terms: D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002097:C-Reactive Protein / Q000378:metabolism*; D018450:Disease Progression; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D011237:Predictive Value of Tests; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000175:diagnosis* / Q000188:drug therapy; D012129:Respiratory Function Tests; D012189:Retrospective Studies
chemical_list: D000900:Anti-Bacterial Agents; D019980:Amoxicillin-Potassium Clavulanate Combination; D002097:C-Reactive Protein